scholarly journals DISCREPANCIES BETWEEN CYTOPHOTOMETRIC FEULGEN VALUES AND DEOXYRIBONUCLEIC ACID CONTENT

1971 ◽  
Vol 19 (3) ◽  
pp. 169-174 ◽  
Author(s):  
K. NOESKE
Keyword(s):  
Functional State ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Cell Types ◽  
Nuclear Proteins ◽  
Feulgen Reaction ◽  
Template Activity ◽  
Colored Product ◽  
Different Cell Types ◽  
Low Template

Diploid nuclei of different cell types of the granulocytopoietic and erythropoietic series showed different Feulgen values. The highest values were found in the most immature nuclei, and the lowest values in the most mature cells. Extraction of acid-soluble nuclear proteins brought the different values to the same level. Examples of similar findings in other cell types, as described in the literature, are discussed. The Feulgen reaction and its colored product depend on the functional state of the chromatin in such a way that nuclei with high template activity of deoxyribonucleic acid show high Feulgen values whereas mature, dense nuclei with low template activity have lower Feulgen values, although both kinds of nuclei contain identical amounts of deoxyribonucleic acid.

scholarly journals DEOXYRIBONUCLEIC ACID CYTOPHOTOMETRY OF STAINED HUMAN LEUKOCYTES I. DIFFERENCES AMONG CELL TYPES

1969 ◽  
Vol 17 (4) ◽  
pp. 249-257 ◽  
Author(s):  
BRIAN H. MAYALL
Keyword(s):  
Visible Light ◽  
Dna Content ◽  
Close Agreement ◽  
Deoxyribonucleic Acid ◽  
Cell Types ◽  
Neutrophilic Granulocytes ◽  
Feulgen Reaction ◽  
Human Leukocytes ◽  
Intensity Measurements ◽  
Individual Human

The deoxyribonucleic acid (DNA) content of individual human leukocytes was estimated cytophotometrically using visible light and spreads stained either with gallocyanin-chrome alum following ribonuclease digestion or with the Feulgen reaction. When the cells were measured on a scanning cytophotometer, significant differences in stain intensity were found among slides. Significant differences also were found among the leukocyte types. In gallocyanin-chrome alum preparations, monocytes measured 16% higher than small lymphocytes and 13% higher than neutrophilic granulocytes. In Feulgen preparations, monocytes measured 4% higher than small lymphocytes and 6% higher than neutrophils. These differences among cell types were independent of donor and stain intensity. Measurements of cells within types and within slides frequently showed close agreement, but it is only in this very limited context that the data are consistent with the hypothesis of DNA constancy. Measurements made on a two-wavelength cytophotometer showed a divergence of only 2.1% relative to similar measurements made on the scanning cytophotometer, which suggests that the differences observed among cells and types are unlikely to be artifacts of the instruments. Over-all, the data indicate either that there is variability in DNA content or that DNA is not being expressed correctly by the measured stain content.

DNA methylation represses the expression of the human erythropoietin gene by two different mechanisms

Blood ◽  
2000 ◽  
Vol 95 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Hong Yin ◽  
K. L. Blanchard
Keyword(s):  
Dna Methylation ◽  
Untranslated Region ◽  
Cpg Island ◽  
Cell Types ◽  
High Density ◽  
Nuclear Proteins ◽  
Proximal Promoter ◽  
Signaling Cascade ◽  
Human Erythropoietin ◽  
Different Cell Types

Abstract The human erythropoietin gene is expressed predominantly in the kidney and liver in response to hypoxia. Although the signaling cascade for hypoxia is present in many different cell types, the expression of erythropoietin is restricted to only a few tissues. The authors show that the promoter and 5′-untranslated region (5′-UTR) of the erythropoietin gene comprise a CpG island and that methylation of the CpG island correlates inversely with expression. Methylation represses the expression of the erythropoietin gene in 2 ways: high-density methylation of the 5′-UTR recruits a methyl-CpG binding protein to the promoter, and methylation of CpGs in the proximal promoter blocks the association of nuclear proteins. (Blood. 2000;95:111-119)

DNA methylation represses the expression of the human erythropoietin gene by two different mechanisms

Blood ◽  
2000 ◽  
Vol 95 (1) ◽  
pp. 111-119 ◽  
Author(s):  
Hong Yin ◽  
K. L. Blanchard
Keyword(s):  
Dna Methylation ◽  
Untranslated Region ◽  
Cpg Island ◽  
Cell Types ◽  
High Density ◽  
Nuclear Proteins ◽  
Proximal Promoter ◽  
Signaling Cascade ◽  
Human Erythropoietin ◽  
Different Cell Types

The human erythropoietin gene is expressed predominantly in the kidney and liver in response to hypoxia. Although the signaling cascade for hypoxia is present in many different cell types, the expression of erythropoietin is restricted to only a few tissues. The authors show that the promoter and 5′-untranslated region (5′-UTR) of the erythropoietin gene comprise a CpG island and that methylation of the CpG island correlates inversely with expression. Methylation represses the expression of the erythropoietin gene in 2 ways: high-density methylation of the 5′-UTR recruits a methyl-CpG binding protein to the promoter, and methylation of CpGs in the proximal promoter blocks the association of nuclear proteins. (Blood. 2000;95:111-119)

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Processing and Characterization of Recombinant von Willebrand Factor Expressed in Different Cell Types Using a Vaccinia Virus Vector

1992 ◽  
Vol 67 (01) ◽  
pp. 154-160 ◽  
Author(s):  
P Meulien ◽  
M Nishino ◽  
C Mazurier ◽  
K Dott ◽  
G Piétu ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Von Willebrand Factor ◽  
Human Fibroblasts ◽  
Active Form ◽  
Cell Types ◽  
Biologically Active ◽  
L Cells ◽  
Von Willebrand ◽  
Different Cell Types ◽  
Willebrand Factor

SummaryThe cloning of the cDNA encoding von Willebrand factor (vWF) has revealed that it is synthesized as a large precursor (pre-pro-vWF) molecule and it is now clear that the prosequence or vWAgll is responsible for the intracellular multimerization of vWF. We have cloned the complete vWF cDNA and expressed it using a recombinant vaccinia virus as vector. We have characterized the structure and function of the recombinant vWF (rvWF) secreted from five different cell types: baby hamster kidney (BHK), Chinese hamster ovary (CHO), human fibroblasts (143B), mouse fibroblasts (L) and primary embryonic chicken cells. Forty-eight hours after infection, the quantity of vWF antigen found in the cell supernatant varied from 3 to 12 U/dl depending on the cell type. By SDS-agarose gel electrophoresis, the percentage of high molecular weight forms of vWF varied from 39 to 49% relative to normal plasma for BHK, CHO, 143B and chicken cells but was less than 10% for L cells. In all cell types, the two anodic subbands of each multimer were missing. The two cathodic subbands were easily detected only in BHK and L cells. By SDS-PAGE of reduced samples, pro-vWF was present in similar quantity to the fully processed vWF subunit in L cells, present in moderate amounts in BHK and CHO and in very low amounts in 143B and chicken cells. rvWF from all cells bound to collagen and to platelets in the presence of ristocetin, the latter showing a high correlation between binding efficiency and degree of multimerization. rvWF from all cells was also shown to bind to purified FVIII and in this case binding appeared to be independent of the degree of multimerization. We conclude that whereas vWF is naturally synthesized only by endothelial cells and megakaryocytes, it can be expressed in a biologically active form from various other cell types.

Role of Transcriptional Read-Through in PRE Activity in Drosophila melanogaster

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin
Keyword(s):  
Dna Sequences ◽  
Cell Types ◽  
Transcription Terminator ◽  
Response Elements ◽  
Polycomb Response Elements ◽  
The Individual ◽  
Multicellular Organisms ◽  
Different Cell Types ◽  
Main Factor

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.

MAPK: A Key Player in the Development and Progression of Stroke

2020 ◽  
Vol 19 (4) ◽  
pp. 248-256
Author(s):  
Yangmin Zheng ◽  
Ziping Han ◽  
Haiping Zhao ◽  
Yumin Luo
Keyword(s):  
Ischemic Stroke ◽  
Signaling Pathway ◽  
Complex Disease ◽  
Therapeutic Targets ◽  
Cell Types ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Effective Prevention ◽  
Prevention And Treatment ◽  
Different Cell Types

Conclusion: Stroke is a complex disease caused by genetic and environmental factors, and its etiological mechanism has not been fully clarified yet, which brings great challenges to its effective prevention and treatment. MAPK signaling pathway regulates gene expression of eukaryotic cells and basic cellular processes such as cell proliferation, differentiation, migration, metabolism and apoptosis, which are considered as therapeutic targets for many diseases. Up to now, mounting evidence has shown that MAPK signaling pathway is involved in the pathogenesis and development of ischemic stroke. However, the upstream kinase and downstream kinase of MAPK signaling pathway are complex and the influencing factors are numerous, the exact role of MAPK signaling pathway in the pathogenesis of ischemic stroke has not been fully elucidated. MAPK signaling molecules in different cell types in the brain respond variously after stroke injury, therefore, the present review article is committed to summarizing the pathological process of different cell types participating in stroke, discussed the mechanism of MAPK participating in stroke. We further elucidated that MAPK signaling pathway molecules can be used as therapeutic targets for stroke, thus promoting the prevention and treatment of stroke.

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